Silicones have properties that make them particularly advantageous in personal care products. Certain silicones produce uniform thin films that are hydrophobic and also produce solutions or emulsions that posses a low viscosity. The low viscosity property allows higher loadings of active ingredients in a cosmetic product without the deleterious effects normally associated with high viscosity products.
In addition, the personal care industry has produced a wide-range of hair care and cosmetic applications that utilize silicones. Among the various products are shampoos to clean the hair and scalp, hair rinses, conditioners, dressings, sprays, coloring and bleaching preparations, permanent waves, and hair straightening and strengthening compositions. Consumers desire a shampoo that foams quickly and copiously and rinses thoroughly leaving the hair with a fresh clean smell and in a manageable state. Further, consumers tend to prefer those shampoos that also leave the hair soft, shiny, lustrous, and full bodied. After shampooing, the hair is usually wet, frequently tangled and thus difficult to comb. Thus it is common for consumers to apply rinses and conditioners to enhance the ease of combing and detangling, to increase hair body, to improve shine and texture, to prevent static buildup, to impart manageability, style retention, and curl retention.
One method of imparting or increasing apparent luster or gloss on the hair is to coat the hair with a material having a high refractive index. Using this technique, the apparent gloss or shine will be proportional to the refractive index of the material on she fiber surface. Absent other factors, a direct proportionality exists between refractive index and apparent shine on hair. Thus higher refractive index cuticle coating formulations will tend to impart a higher shine on hair.